MOT Fail on Emissions

11th March 2011, 15:53

Hi, my vts just had its MOT, and the only thing it got failed on was emissions on fast idle. Now it has a cat etc, what else could this be down to?
thanks

11th March 2011, 15:58

Exhaust blow, If you have a large exhaust tailpipe then they may not of stuffed it, causing oxygen in the air to be picked up.
Faulty llambda probe / o2 sensor, but i would expect your flexy joint near your gearbox mount to be blowing, the bloody things always blow !

11th March 2011, 16:02

the exhaust is standard at the moment, and i dont think its blowing but i havent had a proper look in all honesty. my friend said it could be the coolant temperature sensor maybe? or fuel filter as its the only thing i havent changed? have to get him to check if its blowing though

cheers

11th March 2011, 18:08

just take it somewhere that aint fussed lol!!!!

11th March 2011, 18:18

If your exhaust was blowing it would either fail on that or be on the advisory sheet.

Steve.

11th March 2011, 18:29

My car failed on fast idle last week too, because I haven't had a cat on car and only put it on 15 mins before the MOT. I told the guy at the garage that I did not run a cat before and he advised me to take the car somewhere quite and drive it all the way to red zone as cat has to be run for a while. I took the car for a good spin all the way to 6k and when got back to the test station a mechanic checked emission once again and it passed with flying colours.

11th March 2011, 18:39

You can buy something you put in your oil thats supposed to lower emissions,never tried it myself.

Steve.